Abstract: The performance of lead-acid batteries is significantly affected by temperature. In uninterruptible power supply(UPS) systems,lead-acid batteries are key energy storage components. Excessively high temperatures can accelerate the chemical reaction rate inside the battery,which may lead to overcharging or overdischarging of the battery,thereby affecting its capacity and lifespan. Given this,a well-performing thermal management system(TMS) is indispensable. Its core function is to promptly and effectively dissipate the heat generated by lead-acid batteries under high-load cycling conditions. A hybrid thermal management system(HTMS)that combines phase change materials(PCM)with six flat heat pipes. Under the condition of continuous discharge at a high current of 150 A for 1 400 s without interruption,this system can precisely control the temperature within 40 ℃. During the experiment,two K-type thermocouples(marked as T1 and T2 respectively)were arranged to achieve real-time monitoring of temperature changes. The entire research work covers three typical cases,namely the temperature distribution of batteries under natural convection,the temperature distribution when using heat pipe TMS,and the temperature distribution when using HTMS. The experimental results show that the HTMS system performs exceptionally well in cooling. Compared with the natural convection situation,HTMS can significantly reduce the temperature at T1 by 35%. Under the same comparison conditions,the heat pipe TMS can only reduce the temperature at T1 by 15%.